The aim of this project is to develop a wearable device that records and stores information about how an individual uses his or her voice throughout a day. The device has potential clinical utility since it provides information that clinicians could use to better counsel patients with voice disorders. The device will acquire and store data that describe the phonation time, intensity of the phonation, distribution of fundamental frequency, and intervals of dysphonic phonation. This information, from a period as long as sixteen hours, can be downloaded from the portable device to a computer. Appropriate statistical descriptors of voice use for given time intervals within the day can be derived and displayed from the data. Work in Phase II will be directed at (a) continued testing and refinement of the system developed during Phase I, (b) development of a prototype portable vocal accumulator (PVA) that is small, lightweight and convenient to wear, and (c) field testing of the PVA on normal subjects and patients with voice disorders. Patients will be studied at the Voice and Speech Laboratory of the Massachusetts Eye and Ear Infirmary using procedure worked out successfully during Phase I. PROPOSED COMMERCIAL APPLICATION: Commercial development of the PVA will be sought by licensing the system with an established speech equipment manufacturing company. The major company in this market has already expressed a strong interest in this work.